In recent years, among magnetic cards for recording information in the form data that can be magnetically processed, an increased number of such cards have come to include in their use, in addition to the reading of data recorded, the rewriting of data during the use of the magnetic card. Magnetic cards of this type are, for example, prepaid cards which allow the remaining units of use, the remaining amount of money, etc. to be rewritten each time the card is used.
Hitherto, data on a magnetic card of this type has been rewritten in the following manner: first, the present data is read, then new data is overwritten on magnetic stripes.
As magnetic cards of this type become popular, however, such false acts as forging or copying data on magnetic cards have come to be conducted.
In view of such acts, the card manufacturers have taken counter measures such as to cover a magnetic card with a magnetism concealing layer so as to prevent stealing, forging, etc. of data on the magnetic card. The fact that it is usually difficult for people in general to obtain a magnetic head capable of writing data in a magnetic card, helps to prevent forging of magnetic cards.
However, because a reader-writer for a magnetic card, which is employed during the use of a magnetic card, has a magnetic head capable of writing data, there is a risk that a magnetic head may be obtained from an abandoned reader-writer or the like, and be used in the forging of magnetic cards.
The present invention is intended to overcome said problem conventionally encountered, and to provide a magnetic head for a reader-writer that is effective for preventing forgery, etc. of data in magnetic cards.